Answer:
Explanation:
Remark
The value of the y can be found by using the Geometric Mean. To use the said mean, you must compare parts of one triangle to parts of the second triangle. In this case, the small triangle containing boy 4 and y, must be compared to the triangle use y and 12
Formula
This translates to
4 / y = y/12
Explanation. The two triangles y and 4 and y and 12 are similar. The short side on the small right triangle on the left is 4. The second longest side on the same triangle is y.
In the triangle containing y and 12 The short side is y and the second side length is 12. You have to read this a couple of times to get the meaning of the two ratios.
Solution
4/y = y / 12 Cross multiply
y^2 = 4 * 12
y^2 = 48 Take the square root of both sides.
√y^2 = √48
y = √2 * 2 * 2 * 2 * 3
y = 2 * 2 * √3
Answer
y = 4√3